Being designed to run on on a rough terrain such as a wilderness, an all-terrain vehicle has a wheel suspension device with a cushion whose stroke is set to be strong. Since the stroke is strong, an angle of vertical swing of a constant velocity ball joint transmitting power to wheels becomes large. For this reason, there have been proposed constant velocity ball joints with arrangements made to allow the joints to be applied to all-terrain vehicles (see, for example, Patent Literature 1, FIGS. 4 and 5).
The all-terrain vehicle disclosed in Patent Literature 1 includes a differential gear and front wheels connected by a drive shaft.
A drive shaft of the disclosed vehicle includes a sliding type constant velocity universal joint provided on a differential gear side (inboard side). In the sliding type constant velocity universal joint, a bearing portion is housed within a cup. Also, the bearing portion is housed to be movable in an axial direction along a groove in the cup and be capable of oscillating within the cup.
A fixed type constant velocity universal joint is allowed to move in directions perpendicular to and along an axis of the drive shaft relative to the sliding type constant velocity universal joint.
The length of the groove is determined according to an required amount of movement in the axial direction. As the amount of movement increases, it is required to increase the size of the cup on the inboard side, thereby making the drive shaft expensive.
Since it is required to reduce the cost of an all-terrain vehicle, it is necessary to reduce the cost of a drive shaft.